The adoption of an IP Multimedia Subsystem (IMS) network architecture to merge legacy Voice over IP (VoIP) services with Public Switched Telephone Network (PSTN) services can give rise to interoperability issues. For example, a non-IMS compliant server will not able to redirect a call through an IMS network due in part to a validation process requiring authentication credentials for the calling party number. The call can also fail when the IMS network detects that a communication device associated with the calling party number is not registered in the IMS network or is currently engaged in a call. In yet another scenario, the call can fail when originating treatment is applied to the calling party number by a feature server of the IMS network.
A need therefore arises for a system for communicating with an IMS network.